1. Field of the Invention
This invention relates to an apparatus for treating a semiconductor material such as silicon wafer or glass photomask, and more particularly to a basin for blowing a treatment liquid upwardly against one of surfaces of such a semiconductor material. 2. Description of the Prior Art
Conventional basins of the above sort are each equipped at a lower part thereof with a passage for introducing a treatment liquid thereinto. In combination with each of such conventional basins, a vacuum chuck is employed to suck the semiconductor material thereon by virtue of vacuum and to support the semiconductor material above the basin. Against the semiconductor material supported with one of its surfaces down, said one surface being to be treated, the treatment liquid is blown upwardly so as to bring the treatment liquid into contact with the one surface of the semiconductor material. The treatment liquid which has overflown a top portion of the basin, is then received in a gutter arranged along the circumference of the basin. The thus-received treatment liquid is then returned to a reservoir so as to circulate the treatment liquid. Such conventional basins have cup-like shapes, and nitrogen gas is blown against upper peripheral portions of semiconductor materials placed above the basins so as to prevent the treatment liquid from running astray onto the upper, namely, the rear surfaces of the semiconductor materials.
Due to the cup-like configurations of the conventional basins, the treatment liquid tends to run astray onto the rear surface of each material under treatment. It is thus indispensable to blow nitrogen gas against the material. In addition, the treatment liquid which has hit the intended, namely, the lower surface of the semiconductor material is then converted into a stream flowing along the lower surface of the semiconductor material and another stream splashing back in the downward direction, whereby developing a problem that the treatment liquid cannot be brought into stable contact with the lower surface of the material. Furthermore, bubbles of a gas produced in the course of the reaction between the treatment liquid and the semiconductor material as well as bubbles present in the blown-up treatment liquid tend to stick the semiconductor material. The kinetic energy of the upward stream of the treatment liquid, which has been blown up, is however too small to wash away such bubbles, leading to uneven progress of the reaction due to such bubbles.